Member Spotlight: SnoPUD

About Snohomish County Public Utility District (SnoPUD)

Snohomish County Public Utility District serves one of the fastest growing counties in Washington, delivering electricity to nearly 350,000 customers and water to 20,000 customers. It’s currently the second largest public utility in the Pacific Northwest and the 12th largest in the U.S. It is committed to addressing regional growth by pursuing all cost-effective conservation and a diverse mix of renewable energy sources. The bulk of the PUD’s energy supply comes from clean, renewable hydropower generated in the Pacific Northwest. Other renewable sources include wind energy, solar power, co-generation fueled by wood-waste and biogas.

SnoPUD Demonstrates Energy Storage Technologies

Located in Everett, Wash., SnoPUD has now brought online two energy storage systems at utility substations. The battery storage systems aim to transform the marketplace and how utilities manage grid operations. They also are designed to improve reliability and the integration of renewable energy sources, which are rapidly growing in the Pacific Northwest.

The projects were made possible in part by a $7.3 million investment from the Washington State Clean Energy Fund. The SnoPUD systems are built using an innovative approach known as Modular Energy Storage Architecture (MESA). It offers a non-proprietary and scalable approach to energy storage.

“What sets MESA apart from other energy storage efforts is that it utilizes standard interfaces between equipment components, such as the power conversion system, batteries and control system,” said SnoPUD Senior Manager of Planning, Engineering & Technical Services Jason Zyskowski. “The MESA approach brings more choices for utilities, reduce projects’ complexity and ultimately lower costs.”

MESA was developed by an industry consortium of electric utilities and technology suppliers for the purpose of clearing barriers to growth in energy storage.

Two Systems, Two Technologies

SnoPUD’s first energy storage system includes two large-scale lithium ion batteries, one manufactured by GS Yuasa International Ltd. and supplied by Mitsubishi and a second manufactured by LG Chem. Parker Hannifin manufactured the power conversion systems and battery containerization.

In spring 2017, SnoPUD also completed deployment of its second system, comprised of multiple advanced vanadium flow batteries, built by UniEnergy Technologies. By capacity, it is the world’s largest containerized vanadium flow battery storage system. Together with the lithium ion batteries, these systems will store enough energy to power nearly 1,000 homes for eight hours.

The vanadium flow batteries and control systems are housed in 20 shipping containers, each 20 feet in length, packed with tanks of liquid electrolyte solution. While this technology requires a larger footprint than lithium ion systems, it can store 70 percent more energy and has a longer lifetime.

One of the challenges with past energy storage projects is that each one has been its own black box project. Each of these projects have required a lot of non-recurring engineering costs that are required to make the battery system talk to the power conversion system and talk to the utility systems such as SCADA and DMS. The MESA software creates a common thread. It’s what knits all these things together in a way that promises to unlock the full potential of energy storage.

Future SnoPUD Tech Investments: Microgrids, Vehicle-to-Grid

SnoPUD also is designing a Microgrid & Clean Energy Technology Center in Northern Snohomish County, which will demonstrate new energy technologies including energy storage, a microgrid system, small-scale solar energy and an electric vehicle-to-grid system. This project will show how all of these technologies can work together to improve grid resiliency, disaster recovery and renewable energy integration. The technology center will share a broad range of new energy concepts with researchers, teachers, students and the broader community.